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Potassium and Anorexia. Christina Ferraiuolo HLSC 415. Thesis Question. What is the association between potassium levels in the body and Anorexia Nervosa?. Ice Breaker. Take two What kind of micronutrient is potassium? What relationship would it have with the heart?
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Potassium and Anorexia Christina Ferraiuolo HLSC 415
Thesis Question What is the association between potassium levels in the body and Anorexia Nervosa?
Ice Breaker Take two What kind of micronutrient is potassium? What relationship would it have with the heart? Do you think there is a connection between anorexia and potassium?
Potassium • Potassium is a micronutrient and an electrolyte • Infant RDI 0.4 g/day • Children RDI 3-4 g/day • Adult RDI 4.7 g/day • Breastfeeding RDI 5.1 g/day (Zieve,2009)
Potassium Sources • All meats and fish • Soy products • Fruits: cantaloupe, banana, kiwi, avocado • Vegetables: broccoli, sweet potato, and tomatoes • Milk and yogurt • Nuts(Zieve,2010)
Hypokalemia and Hyperkalemia • Too little potassium in the body is called Hypokalemia • Too much potassium in the body is called Hyperkalemia(Zieve,2009)
Anorexia • An eating disorder • Body Dimorphic • Obsession with weight and food • Starvation • Exercise excessively • Abuse laxatives and diuretics
DSM IV TR Diagnostic Criteria for Anorexia • Intense fear of gaining weight • Distorted self image • Absence of menstrual cycle • Refusal to maintain body weight at healthy range (Dryden-Edwards, 2010)
Anorexia complications • Death • Anemia • Bone loss • Kidney Problems • Brain damage • Heart failure or abnormal heart rhythm • Electrolyte abnormalities (Dryden-Edwards, 2010)
Anorexia and Hypokalemia • Potassium is an electrolyte • Found in food sources • Anorexia patients lose potassium though weight regulation • Fatal electrical alterations of the heart
Thesis Question What is the association between potassium levels in the body and Anorexia Nervosa?
Effect of Weight-Regulating Practices on Potassium Level in Patients with Anorexia or Bulimia Nervosa Imbierowicz,K., Curkovic, I., Braks, K., Gesier, F., Liedtke, R., & Ernst Jacoby, G. (2004). Effects of weight-regulating practices on potassium levels in patients with anorexia or bulimia nervosa. European Eating Disorders Review, 12(5), 300-306. doi: 10.1002/erv.591.
Purpose • To define several diagnostic and symptomatic groups and test them separately for their potassium levels • Anorexia with vomiting • Anorexia with vomiting and laxative abuse • Anorexia without vomiting
Research Design • Descriptive Epidemiological • Cross sectional survey • Examining causal factors associated with different anorexia and bulimic groups with Hypokalemia • Retrospective study
Methods • 397 patients with preexisting eating disorder • Klinik am Korso in Bad Oeynhausen, Germany • Subgroups based on complete symptomatology • Similarities in BMI, age, disease duration • Hypokalemic: < 3.4 mmol/l plasma potassium
Identification of Statistics • Descriptive • Inferential • Correlation tests
Descriptive Statistics • Standard Deviation • Mean • Range • Median
Inferential Statistics • Mann-Whitney U test • Kruskal-Wallis test • Analysis of Variance test (ANOVA) • Post-hoc test (Scheffe’)
Correlation tests • Pearson’s two-tailed testing • Spearman’s correlation testing • Multiple linear regression • Stepwise Linear Regression (R2) • Standardized regression coefficient • Coefficient of determination
Interpretation of Results • Hypokalemia in purging anorexic (p = 0.001) • Hypokalemia in non-purging anorexic (p=0.82) • Higher frequency (p = 0.001) • Severity (p = 0.001) • Differences between anorexic subgroups (p = 0.001)
Results continued • Potassium levels and BMI (r) 0.27 (p=0.001) • Vomiting frequency, laxative abuse and potassium levels (r) -0.38 (p = 0.005) • Mean potassium 2.8 mmol/l
Table 2. Potassium levels and hypokalemia proportion in the subgroups
Weaknesses of the Study • Number of participants • Internal Validity • Recall bias • Selection bias • Confounding variables
Strengths of the Study • Organization • External Validity • Results represent an entire population
Conclusion • Hypokalemia more common in binging and purging anorexics • Potassium losses through stool, urine and vomit • Possibly other factors associated with potassium loss not tested
Thesis Question What is the association between potassium levels in the body and Anorexia Nervosa?
Effects of Anorexia Nervosa on Clinical, Hematological, Biochemical, and Bone Density Parameters in Community-Dwelling Adolescent Girls Mirsa, M., Aggarwal, A., Miller, K., Almazan, C., Worley, M., Soyka, L., et al. (2004). Effects of anorexia nervosa on clinical, hematological, biochemical, and bone density parameters in community-dwelling adolescent girls. Pediatrics, 114(6), 1574-1583. doi:10.1542/peds.2004-0540.
Purpose • To determine the medical effects of anorexia on a young population in terms of normal body function
Research Design • Descriptive Epidemiological study • Cross sectional • Prospective • Community dwelling adolescent girls • Anorexia with outpatient care vs. healthy adolescents • 118 adolescent girls • 60 with DSM IV diagnosed anorexia • 58 healthy- no past history of eating disorder
Methods • Referred by treatment programs in Boston, MA • Prospective data collection at baseline visit • Three month or more community dwelling • Biochemical • Potassium levels • Anthropometric • BMI
Identification of Statistics • Descriptive statistics • Inferential statistics
Descriptive Statistics • Mean • Standard Deviation
Inferential Statistics • T-test • Univariate regression analysis • Correlation between variables • Stepwise regression analysis • Significant predictors
Interpretation of Results • Mean serum potassium levels higher in anorexic • AN: 3.8 +/- 0.3 mmol/l • Healthy: 3.6 +/- 0.2 mmol/l • no subject Hypokalemic • Serum potassium< 3.0 mmol/l • Two subjects with history of purging behavior
Weaknesses of the Study • Weakness in planning • No hypothesis stated • Limited external validity
Strengths of the Study • Comparability to the control and observed group • Diverse referrals decrease selection bias • Limited external validity • Caucasian Adolescent female specific
Conclusion • Normal serum potassium levels • Higher in anorexic • Due to dehydration • Total potassium levels may still be low • Not at risk even with low BMI • Still at risk for cardiac abnormalities • No purging behaviors observed
Thesis Question What is the association between potassium levels in the body and Anorexia Nervosa?
Overall Conclusion • Potassium levels are influenced by Anorexia • Both suggested potential cardiac risk • Differences in studies • Set potassium level as Hypokalemic • Population studied
Did I answer my question? • Yes! • Both saw changes in extracellular potassium in the Anorexic populations
Future Direction • More research in diverse groups • Identify relationship of purging and potassium levels • Identify other variables not accounted for • Measuring total potassium vs. only plasma